Dr Holly-May Lewis

Research Fellow

Academic and research departments

Ion Beam Centre, Department of Chemistry.


Holly-May Lewis, Yufan Liu, Cecile F. Frampas, Katie Longman, Matt Spick, Alexander Stewart, Emma Sinclair, Nora Kasar, Danni Greener, Anthony D. Whetton, Perdita E. Barran, Tao Chen, Deborah Dunn-Walters, Debra J. Skene, Melanie J. Bailey (2022)Metabolomics Markers of COVID-19 Are Dependent on Collection Wave, In: Metabolites12(8)713 MDPI AG

The effect of COVID-19 infection on the human metabolome has been widely reported, but to date all such studies have focused on a single wave of infection. COVID-19 has generated numerous waves of disease with different clinical presentations, and therefore it is pertinent to explore whether metabolic disturbance changes accordingly, to gain a better understanding of its impact on host metabolism and enable better treatments. This work used a targeted metabolomics platform (Biocrates Life Sciences) to analyze the serum of 164 hospitalized patients, 123 with confirmed positive COVID-19 RT-PCR tests and 41 providing negative tests, across two waves of infection. Seven COVID-19-positive patients also provided longitudinal samples 2–7 months after infection. Changes to metabolites and lipids between positive and negative patients were found to be dependent on collection wave. A machine learning model identified six metabolites that were robust in diagnosing positive patients across both waves of infection: TG (22:1_32:5), TG (18:0_36:3), glutamic acid (Glu), glycolithocholic acid (GLCA), aspartic acid (Asp) and methionine sulfoxide (Met-SO), with an accuracy of 91%. Although some metabolites (TG (18:0_36:3) and Asp) returned to normal after infection, glutamic acid was still dysregulated in the longitudinal samples. This work demonstrates, for the first time, that metabolic dysregulation has partially changed over the course of the pandemic, reflecting changes in variants, clinical presentation and treatment regimes. It also shows that some metabolic changes are robust across waves, and these can differentiate COVID-19-positive individuals from controls in a hospital setting. This research also supports the hypothesis that some metabolic pathways are disrupted several months after COVID-19 infection.

Matt Spick, Holly-May Lewis, Cecile F. Frampas, Katie Longman, Catia Costa, Alexander Stewart, Deborah Dunn-Walters, Danni Greener, George Evetts, Michael J. Wilde, Eleanor Sinclair, Perdita E. Barran, Debra J. Skene, Melanie J. Bailey (2022)An integrated analysis and comparison of serum, saliva and sebum for COVID-19 metabolomics, In: Scientific reports1211867 Nature Portfolio

Abstract The majority of metabolomics studies to date have utilised blood serum or plasma, biofluids that do not necessarily address the full range of patient pathologies. Here, correlations between serum metabolites, salivary metabolites and sebum lipids are studied for the first time. 83 COVID-19 positive and negative hospitalised participants provided blood serum alongside saliva and sebum samples for analysis by liquid chromatography mass spectrometry. Widespread alterations to serum-sebum lipid relationships were observed in COVID-19 positive participants versus negative controls. There was also a marked correlation between sebum lipids and the immunostimulatory hormone dehydroepiandrosterone sulphate in the COVID-19 positive cohort. The biofluids analysed herein were also compared in terms of their ability to differentiate COVID-19 positive participants from controls; serum performed best by multivariate analysis (sensitivity and specificity of 0.97), with the dominant changes in triglyceride and bile acid levels, concordant with other studies identifying dyslipidemia as a hallmark of COVID-19 infection. Sebum performed well (sensitivity 0.92; specificity 0.84), with saliva performing worst (sensitivity 0.78; specificity 0.83). These findings show that alterations to skin lipid profiles coincide with dyslipidaemia in serum. The work also signposts the potential for integrated biofluid analyses to provide insight into the whole-body atlas of pathophysiological conditions.

Holly-May Lewis, Roger Webb, Guido F Verbeck, Josephine Bunch, Janella De Jesus, Catia Costa, Vladimir Palitsin, John G. Swales, Richard J. A. Goodwin, Patrick Sears, Melanie Jane Bailey (2019)Nanoextraction coupled to liquid chromatography mass spectrometry delivers improved spatially resolved analysis, In: Analytical Chemistry91(24)pp. 15411-15417 American Chemical Society

Direct analyte probed nanoextraction (DAPNe) is a technique that allows extraction of drug and endogenous compounds from a discrete location on a tissue sample using a nano capillary filled with solvent. Samples can be extracted from a spot diameters as low as 6 µm. Studies previously undertaken by our group have shown that the technique can provide good precision (5%) for analysing drug molecules in 150 µm diameter areas of homogenised tissue, provided an internal standard is sprayed on to the tissue prior to analysis. However, without an isotopically labelled standard, the repeatability is poor, even after normalisation to and the spot area or matrix compounds. By application to tissue homogenates spiked with drug compounds, we can demonstrate that it is possible to significantly improve the repeatability of the technique by incorporating a liquid chromatography separation step. Liquid chromatography is a technique for separating compounds prior to mass spectrometry (LC-MS) which enables separation of isomeric compounds that cannot be discriminated using mass spectrometry alone, as well as reducing matrix interferences. Conventionally, LC-MS is carried out on bulk or homogenised samples, which means analysis is essentially an average of the sample and does not take into account discrete areas. This work opens a new opportunity for spatially resolved liquid chromatography mass spectrometry with precision better than 20%.

Imesha De Silva, Amanda R Kretsch, Holly-May Lewis, Melanie Bailey, Guido Fridolin Verbeck (2019)True One Cell Chemical Analysis: A Review, In: The Analyst144pp. 4733-4749 Royal Society of Chemistry

The constantly growing field of the true one cell analysis provides important information on the direct chemical composition of various cells and cellular compartments. Since the heterogeneity of individual cells has been established, more researchers are interested in the chemical differences between individual cells and that is the only analysis of the one cell can determine. This results in new technologies and methods being reported regularly. This review highlights the common techniques of micro- and nanomanipulation, Raman spectroscopy, microsocopy, and mass spectrometric imaging as they pertain to the true one cell chemical analysis.

Matt Spick, Holly M. Lewis , Michael J. Wilde , Christopher Hopley, Jim Huggett , Melanie J. Bailey (2021)Systematic review with meta-analysis of diagnostic test accuracy for COVID-19 by mass spectrometry, In: Metabolism Elsevier

Background The global COVID-19 pandemic has led to extensive development in many fields, including the diagnosis of COVID-19 infection by mass spectrometry. The aim of this systematic review and meta-analysis was to assess the accuracy of mass spectrometry diagnostic tests developed so far, across a wide range of biological matrices, and additionally to assess risks of bias and applicability in studies published to date. Method 23 retrospective observational cohort studies were included in the systematic review using the PRISMA-DTA framework, with a total of 2 858 COVID-19 positive participants and 2 544 controls. Risks of bias and applicability were assessed via a QUADAS-2 questionnaire. A meta-analysis was also performed focusing on sensitivity, specificity, diagnostic accuracy and Youden’s Index, in addition to assessing heterogeneity. Findings Sensitivity averaged 0.87 in the studies reviewed herein (interquartile range 0.81 - 0.96) and specificity 0.88 (interquartile range 0.82 - 0.98), with an area under the receiver operating characteristic summary curve of 0.93. By subgroup, the best diagnostic results were achieved by viral proteomic analyses of nasopharyngeal swabs and metabolomic analyses of plasma and serum. The performance of other sampling matrices (breath, sebum, saliva) was less good, indicating that these protocols are currently insufficiently mature for clinical application. Conclusions This systematic review and meta-analysis demonstrates the potential for mass spectrometry and ‘omics in achieving accurate test results for COVID-19 diagnosis, but also highlights the need for further work to optimize and harmonize practice across laboratories before these methods can be translated to clinical applications.